History says that a 7.5-magnitude earthquake struck in 1869 in the same area of Sylhet. In 1989, a 7.6-magnitude earthquake happened there. The last one, a 7.1 magnitude Durgapur earthquake occurred in 1923.
In the past, three major earthquakes, including small ones, struck in 60-70 kilometre area of Sylhet. Last month, there was an earthquake in Assam which did not affect Bangladesh but caused damage there.
Small earthquakes indicate a large-scale earthquake in the future. Over 150 years, high-magnitude earthquakes have been occurring in the area.
There are two types of scientific opinions regarding earthquakes among experts. One group says that when mild earthquakes happen, large ones do not happen. The second opinion is small earthquakes is a warning for large ones.
I believe in the latter one. Recently, incidents of earthquakes have increased in the area. It may take one or two years for the next earthquake to come and we need to take comprehensive preparation. The main damage in an earthquake is the collapse of buildings. As much as 90% of residents die after a building collapses.
Sylhet City Corporation as well as Dhaka City Corporation should examine the condition of buildings to determine the effects of earthquakes on them.